The width of an agricultural machine has an impact on the capacity that can be obtained from the machine. A trend in the design of agricultural machines, especially for harvesters and other equipment used to traverse a field, is for the size of the machines to become larger, reducing the number of passes required to cover a field. Agricultural harvesters, such as combines, include a head and a feeder housing which remove the crop material from the field, gather the crop material and transport the crop material to a separator in the harvester. The separator removes the grain crop material from the non-grain crop material. As the width of a harvester is increased, more crop material is processed and harvested. As a result, it is necessary to increase the capacity of processing equipment and crop storage bins on the harvester. The supporting structure, including the chassis and wheels, must be enlarged to provide the necessary stability for the overall larger size of the equipment. It is sometimes found necessary to increase the wheelbase of the equipment both in the distance between axles and in the width of the axle assembly to provide the necessary stability.
The maximum machine width attainable is limited by restrictions in allowable shipping within many countries. Machine configurations that maximize functional machine width and minimize transport width are desirable for providing increased capacity and productivity within a shippable overall configuration.
In some situations, the agricultural equipment is transported frequently. Accordingly, it is desirable that the “setup” process to prepare for shipping be performed quickly and efficiently. It is known to remove the cutting head for transport, and to remove wheels to reduce the machine with. Each of these can be done efficiently. With the cutting head removed, the widest point is often the distance from the outside tire surface of one wheel to the outside tire surface of the other wheel on the widest axle. Accordingly, it is known to remove the wheels from the wheel hubs to further reduce the machine width. Even this may be insufficient to meet maximum shipping width requirements, thus necessitating buying over-width shipping permits where available, or constraining the ability to market equipment in regions having firm over-width limits.
What is needed in the art is an axle assembly that can be extended beyond the shipping widths for providing stability on even the widest machines, and which can be narrowed significantly to meet stringent size limitations for shipping.